The Digestive System

• Lesson topic is the digestive system

Digestive System Organs

• The digestive system includes the gastrointestinal tract, liver, pancreas, and gallbladder
• The liver, pancreas, and gallbladder are solid organs
• The gastrointestinal tract consists of hollow organs
• The gastrointestinal tract starts at the mouth and includes the esophagus, stomach, small intestine, large intestine, rectum, and anus
• Gut flora, or microbiome, aids in digestion within the gastrointestinal tract
• The digestive process involves a combination of nerves, hormones, bacteria, blood, and digestive system organs

The Digestion Process

• Complex molecules in food must be broken down for energy
• Digestion is the process of breaking food down into smaller molecules
• These smaller molecules are then absorbed into the body
• Digestion occurs in two stages: mechanical and chemical
• Mechanical digestion involves physically breaking down food through actions like tearing, biting, cutting, grinding, and mashing
• Mechanical digestion involves teeth and tongue reducing food to a fine mixture
• Chemical digestion uses digestive enzymes after mechanical digestion
• Digestive enzymes further break down food into a soluble form

Path of Digestion

• Food's journey begins when the tongue pushes food into the throat during swallowing
• The epiglottis prevents choking by folding over the windpipe as food passes into the esophagus
• The brain signals the esophagus muscles to initiate peristalsis
• Peristalsis is wave-like muscle contractions that move food
• At the end of the esophagus, the lower esophageal sphincter relaxes to allow food into the stomach
• The lower esophageal sphincter usually remains closed to prevent food from flowing back into the esophagus
• The stomach mixes food and liquids with digestive juices to create chyme
• The stomach then transfers chyme into the small intestine
• The small intestine further mixes food with digestive juices from the pancreas, liver, and intestine
• Small intestine walls absorb water and nutrients into the bloodstream
• Peristalsis continues moving waste products to the large intestine
• The large intestine absorbs water from the waste, turning it into stool
• Stool is temporarily stored in the rectum before being pushed out through the anus during a bowel movement
• Epiglottis is a leaf-shaped flap of cartilage located behind the tongue that closes the larynx during eating to prevent food inhalation
• Chyme is the pulpy, acidic fluid that moves from the stomach to the small intestine, which contains gastric juices and partially digested food
• Stool consists of undigested food, bacteria, mucus, and cells from the lining of the intestines

Assimilation

• The body derives energy from the nutrients absorbed by cells
• Assimilation refers to the transportation and utilization of absorbed nutrients
• Simple sugars like glucose, fructose, and galactose are converted to glycogen for storage in the liver
• Some glucose is carried in the blood for distribution throughout the body and energy production
• Proteins convert into amino acids, which help to grow and repair body parts; they are also useful when forming enzymes and hormones
• Fats convert into fatty acids and glycerol, key parts of cell membranes, and excess fats are stored in adipose tissue

Digestive enzymes

• Digestive enzymes are key to breaking down food, where proteins accelerate chemical reactions to transform nutrients for absorption in the digestive tract
• Ptyalin, or salivary amylase, produced in the mouth, helps break down large starch molecules into smaller sugar molecules
• Pepsin produced in the stomach, helps break down proteins into amino acids
• Lipase, produced in the pancreas, helps break apart fats into droplets or globules
• Mucin is a digestive enzyme produced in the salivary glands
• Pepsin is a digestive enzyme produced in the gastric glands
• Pancreatic amylase, trypsin and lipase are digestive enzymes produced in the Pancreas
• Lactase, maltase, sucrase, peptidase, and lipase are digestive enzymes produced in the intestinal glands

Cell division

• Cell division is essential for growth and repair in multicellular organisms
• Cell division allows unicellular organisms to reproduce asexually
• There are two types of cell division depending on the purpose: meiosis and mitosis
• Meiosis is for sexual reproduction
• Mitosis is for growth and cell replacement
• Cells alternate between stages of division and rest, called the cell cycle

Interphase

• Interphase is the non-dividing stage devoted to cell growth
• Interphase includes three phases: Gap 1 (G1), Synthesis (S), and Gap 2 (G2)
• The cell grows and prepares for division during the Gap 1 (G1) phase, where RNA and DNA are synthesized
• During the Synthesis (S) phase, DNA is synthesized and chromosomes replicate
• RNA and proteins continue to be synthesized as the cell continues to grow in Gap 2 (G2)

Mitosis

• Mitosis is the division of the nucleus that results in two identical daughter cells
• The four stages of Mitosis are prophase, metaphase, anaphase, and telophase
• During prophase, chromosomes coil up, nucleoli and nuclear membranes disappear, and spindle fibers form
• Metaphase involves the alignment of double-stranded chromosomes at the middle of the nucleus
• The centromeres divide in anaphase, and single-stranded chromosomes move to opposite poles
• Telophase is the “reverse prophase,” where chromosomes uncoil and nucleoli and nuclear membranes reappear, and spindle fibers disappear
• Spindle fibers are thread-like material that chromosomes attach to and align during division

Cytokinesis

• When cells divide, it involves the nucleus and the cytoplasm
• Cytokinesis refers to the division of cytoplasm
• In plant cells, cytokinesis involves a cell plate formation that develops into the cell wall
• In animal cells, cytoplasmic division occurs through the formation of a cleavage furrow

Meiosis

• Meiosis is the cell division associated with sexual reproduction.
• Meiosis involves a single cell dividing twice, resulting in four daughter cells
• These daughter cells called sperm or egg only have half the number of chromosomes of the parent cell.
• Meiosis consists of two divisions: meiosis I and meiosis II
• Both divisions of meiosis follow the same stages as mitosis: prophase, metaphase, anaphase, telophase

Genetics Terminology

• Gene segment of DNA and the base of heredity

• Allele is an alternative from of a gene that controls specific genes

• Trait is a distinguishing characteristic

• Dominant allele expresses itself and hides the effects of the recessive allele for a trait. It is represented by a capital letter

• Recessive allele is only expressed if in a homozygous state, and is represented by a lowercase letter

• Heterozygous organism having two different alleles of a particular gene (e.g., Bb)

• Homozygous organism having two identical alleles of a particular gene: BB or bb

• F1 generation the first filial generation

• Monohybrid cross involves organisms that track down only on the trait of an organism Punnett square visualizes all combinations of genes from parents

• Genotype genes present in an organism

• Phenotype observable physical appearance of an organism

Monohybrid cross

• A tool for genetics problem solving
• Can predict traits following inheritance

Dihybrid cross

• Is when two different traits are allowed to pollinate
• Can generate offspring ratio for traits

Laws of Genetics

• Genes come in pairs and are inherited as distinct units
• Segregation refers to how pure breeding parent plants have two identical genes for a trait.
• Independent assortment refers to the fact that genes for different traits are sorted separately so that the inheritance of one trait is not dependent on the inheritance of another.
• Law of dominance details that organisms will always express the form that is dominant, it is just that is recessive if both factor are recessive.

Biodiversity

• Is also known as "biological" "diversity"
• Refers to all life like animals, plants, fungi
• Includes wildlands, nature preserve, and national parks
• Rainforests tend to have the highest biodiversity

Classification of Organisms

• Classifications consist of domain, kingdom, phylum, class, order, family, genus, and species.
• Binomial nomenclature is what we called the standardized and internationally accepted way of writing animal names. It was created by Cral Linnaeus.

5 Kingdom

• 5 kingdom scheme was developed by Robert Whittaker
• There are five kingdoms: Animalia, Plantae, Fungi, Protista, and Monera
• Organisms are diverse in that they need to be classified based on their structural organization and method of nutrition.

Atomic Theory, Protons, & Neutrons

• Matter is made of elements
• Elements are found in the periodic table
• Atoms are composed of protons, neutrons, and electrons
• Protons are positive
• Neutron have no charge and are neutral
• Electrons are negativley charged
• Atoms include a nucleus of positive protons and neutral neutrons, orbited by negative electrons
• Ernest Rutherford discovered protons in 1919
• Protons are central to determining the unique properties of individual atoms
• Quarks are contained protons
• strong force that sticks the quarks together helps

Atomic Mass

• Is the total parts in the nucleus
• Can be determined using the formula: mass number=(number of protons) + (number of neutrons)

Electrons

• Electrons have a negative charge.
• Negatively charged particles of an atom
• Form create a negative charge that balances the positive charge of the protons in the atomic nucleus.
• Are extremely small compared to all of the other parts of the atom.
• Surround the nucleus of an atom

The number of electrons in an atom

• Is the same as the atomic number of an element
• In a neutral atom, the negative electrons should balance the positive charge of the protons.
• Hydrogen, with an atomic number of 1, has one proton and one electron.

Atomic Orbitals

• Modern scientific research finds we cannot determine exactly where an electron location.
• Modern physics tells us that the electron is most likely to be found in a region of space outside the nucleus. This region of space is called an orbital
• Different orbitals have different shapes and different energies
• Principal quantum number (n), orbital quantum numbers (l), and spin quantum number (s) determine energy level
• quantum refers to a quantity of energy
• Lower quantum number describes a lower level of energy
• Principal quantum number n describes the average distance of the orbital from the nucleus and the energy of the electron in an atom.
• The orbital quantum number l describes the shape of the orbital, and it depends
• Spin quantum number can only take numbers of spin-up or spin-down.
• Sublevel has either a spherical or dumbbell shaped orbitals

Electrons arrangement in orbitals

• Aufbau is the first important factor that indicates which electron occupies the lowest energy
• Exclusion principle has help detail that no two electrons can have exactly the same set of quantum numbers
• Hund's rule states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbital.

Electron configuration

• A way to show proper filling of orbitals

Periodic Table of Elements

• elements on it
• Has properties and is based on the number of protons
• Number of protons is the atomic number
• Each elements are represented by symbols
• IUPAC oversees the PToE

Metalloids

• They have both types of properties
• Allow electric current to flow

Noble gases

• Similar with certain properties
• Valence electrons form gasses

Periodic law

• Periods are hoorizontal and have families named halogens
• System with Roman numerals is called IA, IIA, and VIIA

Classify matter

• Matter can be classifies by phases like solid, liquid, and gas
• Particles in orderly way are held together
• There are a set distance between forces

Change of phases

• Transformation from one state to another is a change of phrase
• Heat can be absorbed in process that are called endothermic
• The releases of heat is called exothermic
• Example include melting and condensations

Phase change

• Atoms or molecules make up a solid substance that are strongly attracted
• Phase that has heat is heat energy by the particles.
• Energy has converted such as the kinetic energy and the particles vibrate and rotate faster.
• Eventually, when the energy is sufficient enough to overcome the strong forces of attraction between the particles, they break away from their fixed positions and solid is converted to liquid. This process is called melting or fusion. The temperature at which a substance begins to melt is called melting point. Different substances have different melting points.
• When a liquid is cooled, the particles slow down such that the attractions begin to overcome the motion. The attractions between particles cause them to settle in more fixed and orderly positions and become solid. This process is called freezing or solidification.

Evaporation

• That occur when the energy from the bumping is more than the force.
• High temepratures
• Fast evaporation

Sublimation

• Occurs directly and allows solid to gas and to go around forces and be in solid dry form.

Earthquakes

• Quakes are a vibration in the Earth’s crust or a trembling or shaking movement
• Rocks that cannot stand the interior slip and cause them
• Energy is in vibration
• Seismology is the study

Vocabulary

• Tectonic plates are Earth is brokedn into
• Fault line shift due to plates

Dip-Slip

• Are inclined vertically
• Normal where the weak earthquake is produced by plates being moved
• Reverse is push forward by earthquake

Strike-Slip

• Formed between layers and are lateral.
• The focus shift and is from movement.
• Hypocenter for where the shift is.

Bodies

• Waves are low intensity that cause main shock
• Surface waves are earthquake
• Love waves move earthquake

Secondary s-waves

• Occur when matter that passes move in perpendicular angle

Measure seismic

• In different ways intensity and magnitude
• Intensity is the how fast and shaking
• The Richter helps describe the earthquake
• Seismograph is an instrument that measure it

Tsunamis

• Push occur when force happens under
• generated by earthquakes near water
• 7.5 Richter is what you ned to make one

Quakes

• Release different types of energy
• May vary, level to prepare and population density
• Time is important and may cause people to be trapped. Loose soils cause it Members of the solar system

Different orbits

• Have different types of planets
• Have the sun
• Have asteroids